A child's ability to initiate and maintain a positive and competent interaction with peers is among the most important developmental tasks of childhood, particularly at the time when children make a transition from the family to broader social systems (between 4 and 6) years of age. Both family influences, and the child's temperamental qualities, such as shyness, have been implicated as important determinants of a child's success in peer relations. Children of depressed mothers may be at a particular risk, because of a variety of maladaptations existing at home, as well as possible greater vulnerabilities to withdrawal and inhibition. To address these issues, children of normal and depressed mothers (sample from the Protocol 79-M-123) are being studied at age 5, while interacting with an unfamiliar peer.